172 ZOOLOGY 
groove, whose other side is formed by a lip which also runs 
round the edge of the lophophore (Fig. 109). The tentacles are 
partially ciliated as well as grooved, and any particles of 
food they come in contact with are carried down the 
groove to the mouth, which opens in its posterior median line. 
In other genera the lophophore stands out from. the surface of 
the body and becomes curiously coiled and rolled up, as in 
Waldheimia (Fig. 111), in which animal it is supported by a 
calcareous loop. 
The mouth is a transverse slit leading into a_ short 
oesophagus; this is attached by mesenteric strands to the 
Fic. 109.—Transverse section through the middle of Avrgiope neapolitana. The 
section includes the posterior limit of the lophophore, but is anterior to the 
brood pouches. 
1. Stomach. 7. Ventral shell. 
2. Gastroparietal bands. 8. Vascular canal in shell. 
3. Ovary in dorsal shell. 9. Canal at base of lophophore, which 
3’, Ovary in ventral shell. sends a branch into each tentacle. 
4, Dorsal adjustor muscle. 10. Lip forming with the tentacles a 
5. Occlusor muscle. groove. 
6. Left mesentery; posteriorly this 11. Dorsal shell. 
fuses with the right to form a 
single mesentery. 
end of the median projection of the dorsal shell, and it opens 
directly into the globular stomach. On each side of the aliment- 
ary canal is the liver, composed of six or seven thick tubules, 
which unite and open into the stomach by a broad mouth. 
The lumen of the liver is often full of secretion, it is lined by 
vacuolated cells. The stomach opens behind into a short intes- 
tine which has no anus, and which, like the rest of the aliment- 
